Manning was sacked by MK Dons in December after a poor run of form and his side mired in the relegation zone in League One.
Portsmouth are looking for a successor to Danny Cowley and interviewed Manning last weekend.
And it is suggested the most noise at the moment points towards Portsmouth handing Manning the reins at Fratton Park.
Manning’s interview is also claimed not to be the first time that he has spoken with Portsmouth.
Portsmouth were beaten 3-0 by Bolton Wanderers on Saturday and sit a lowly 15th in the League One standings.
They have lost ground on the playoff places and are now nine points off sixth placed Barnsley.
Pompey return to the comforts of Fratton Park next weekend when Exeter City are the visitors and it remains to be seen if they will have a new man at the helm by then.
